1. Field of the Invention
The present invention relates to an input buffer for digital signal circuits, and more specifically to an input buffer for comparing an input voltage signal with a reference voltage and amplifying the voltage difference between the output voltage signal and the reference voltage.
2. Description of Related Art
At present, various types of input buffers have been proposed and used in the field of integrated circuit memories. For a stable and regular operation, the input buffers should have (1) a function of holding an input voltage and hence an output signal; (2) a narrow insensible band or zone in an input level discrimination; and (3) a simple circuit construction.
However, some conventional input buffers cannot retain an output data, and therefore, if the input buffer is used, a circuit connected to receive an output of the input buffer has been required for input information. As a result, the overall construction of the circuit including the input buffers had to have an increased number of circuit elements. Furthermore, the conventional input buffers have been required to provide a one-shot circuit for elevating the level of an input signal and also capable of receiving a latch signal for introducing an input signal to the input buffer.